The reason for this is that the programs in /tools are no longer needed. Since they are no
longer needed you can delete the /tools
directory if so desired.

Note

Removing /tools will also remove the
temporary copies of Tcl, Expect, and DejaGNU which were used for
running the toolchain tests. If you need these programs later on,
they will need to be recompiled and re-installed. The BLFS book has
instructions for this (see http://www.linuxfromscratch.org/blfs/).